Infectious Agents Cause About One in Six Cancers Worldwide
Infection-attributable cancers are more likely in less developed regions worldwide
WEDNESDAY, May 9 (HealthDay News) -- Globally, nearly two million new cancer cases are caused by infectious agents each year, according to a study published online May 9 in The Lancet Oncology.
Catherine de Martel, M.D., from the International Agency for Research on Cancer in Lyon, France, and colleagues utilized statistics on estimated cancer incidence in 2008 to calculate the population attributable fraction (PAF) of infectious agents classified as carcinogenic to humans, worldwide and in eight geographic regions. Calculations were based on the prevalence of infection in cancer cases rather than in the general population, when the associations were very strong.
The researchers found that, of the 12.7 million new cancer cases that occurred in 2008, the PAF for infectious agents was 16.1 percent. This represented about two million new cases. The fraction of infection-attributable cancers was higher in less developed countries than in more developed countries (22.9 versus 7.4 percent). Approximately 1.9 million cases of gastric, liver, and cervix uteri cancers were caused by Helicobacter pylori, hepatitis B and C viruses, and human papillomaviruses. Cervix uteri cancer accounted for about half of the infection-related burden of cancer in women, while liver and gastric cancers accounted for more than 80 percent in men. Younger people (<50 years) were affected by approximately 30 percent of infection-attributable cases.
"Around two million cancer cases each year are caused by infectious agents," the authors write. "Application of existing public health methods for infection prevention, such as vaccination, safer injection practice, or antimicrobial treatments, could have a substantial effect on the future burden of cancer worldwide."